Acanthomola pubescens, a new genus and species of Heptageniidae (Ephemeroptera), is described from larvae collected in Saskatchewan and Alberta. Acanthomola superficially resembles Bleptus, Epeorus, and Raptoheptagenia, but differs from these genera, and all other heptageniids, in the structure of the mandibles and maxillae. The molar area of the mandible is greatly reduced and bears only a few stout spines. The crown of the maxillary galea-lacinia is rounded and lacks setae near the apex. The apical segment of the maxillary palpus is long, slender, and bare. Generic and specific descriptions of the larva of A. pubescens, gen. nov., sp. no v., are given, along with biological notes. Acanthomola appears to be a very primitive heptageniid, related to Bleptus, Epeorus, and Ironodes. It is probably most closely related to Spinadis.

Omalorphanus new genus is described to include the new species O. aenigma from the Cascade Range of Oregon. The species is tentatively assigned to the subfamily Omaliinae, tribe Anthophagini; the characters on which this assignment is based and the morphological features that distinguish it from other Omaliinae are thoroughly discussed.

Respiration rates and drowning times after complete submergence were observed in diapausing Heliothis zea (Boddie) pupae at 5, 10, 15, 20, and 27°C. Respiration rate in pupae 2.5–12 weeks in diapause increased as an exponential function of temperature. The respiration rate of post-diapause pupae at 27°C increased over 10-fold in an approximately linear fashion during 12 days of pharate adult development. Time to 50% drowning in diapausing pupae decreased with increasing temperature, varying from 22.9 to 4.1 days at 5 and 27°C, respectively. Drowning rates in these pupae increased approximately exponentially with temperature. Diapausing and post-diapause pupae at 27°C had similar times to 50% drowning. An empirical model of drowning fitted the results well at all five temperatures, but a mechanistic model based on respiration predicted drowning considerably before it was observed. When the latter model was modified to allow withdrawal of dissolved oxygen from the water, it predicted longer survival periods, as observed. Our evidence suggests that respiration and drowning rates are closely correlated. Given the long survival times under complete submergence at 5–20°C, we speculate that pupae overwintering in the field in deep diapause are relatively resistant to drowning, whereas pre- and post-diapause pupae, with higher respiration rates, are at much greater risk.

The demographic statistics and the temperature requirements for development of Ephedrus californicus Baker were determined under constant laboratory conditions. At 23 °C, females provided each day with forty 2nd-instar pea aphids, Acyrthosiphon pisum (Harris), lived for 13.4 days and laid 1193 eggs on average; the highest fecundity of any female was 1762 eggs. For an assumed population sex ratio of 1:1 males to females, the intrinsic rate of increase, r, was 0.371 females·female−1·day−1 when all eggs laid were counted. The lower temperature threshold for development, t, was estimated as 6.83 °C, and the time-to-adult, K, as 228.9 degree-days. The potential use of E. californicus in the biological control of the lupine aphid, Macrosiphum albifrons Essig, in England is considered.

The abundances of eight species of cutworm and armyworm moths were monitored with sex-attractant traps at 81 locations in a 13 000-km2 area of southern Alberta from 1978 to 1983. The life history and economic status of each species is summarized and the monitoring methodology is described. The attractants for redbacked cutworm (Euxoa ochrogaster), darksided cutworm (Euxoa messoria), pale western cutworm (Agrotis orthogonia), and army cutworm (Euxoa auxiliaris) were highly specific and > 99% of the moths caught were of the target species. Specificity of the attractants for clover cutworm (Discestra trifolii) and Leucania commoides was also high, averaging 98.3 and 96.6%, respectively, over 6 years. The attractants for variegated cutworm (Peridroma soucia) and bertha armyworm (Mamestra configurata) were less specific but the proportion of target species exceeded 80% in those years when either species was relatively abundant. For those species that were monitored over a wide range of population levels, the apparent specificity of the attractant varied directly with the number of target species moths caught. The use of efficient attractants in combination with high-capacity nonsaturating traps is clearly of advantage in enhancing specificity.

Dissections of flies caught attacking cattle and flying over the Athabasca River (14 June through 11 September 1974) revealed two large peaks of nulliparous females and two peaks of parous females. In both cases, peak numbers of nullipars preceded the peaks in pars. A small third cohort emerged in late August, and some nullipars were collected over the river on all sampling dates.

Around cattle, nullipars had two prominent, but brief, peaks, followed by two subsequent prolonged periods when pars were most abundant. Parity of captured females was typical of the expected seasonal pattern of parity for an anautogenous species and corroborated our previous determination of obligate anautogeny of laboratory-reared females.

Females examined for parity status were categorized as being teneral, blood-fed, gravid/ovipositing, or parasitized with a mermithid parasite (Isomermis spp.). Dissection of 2414 flies caught over the river revealed little difference in the infection rates of males and females throughout the season. Mermithids occurred primarily in nulliparous flies of the first generation and retarded the development of the reproductive organs in both sexes. Parasitism did not prevent nulliparous females from mating, nor feeding on carbohydrate or blood. A blood meal actually seemed required for maturation of the mermithid parasite. Blood-engorged females with mermithids were collected both around cattle and flying over the Athabasca River. When parasitized females with digested blood meals joined swarms of ovipositing females, mermithids were returned to the river. Nearly all flies harbored just one worm; of the 1435 parous females examined for parity, only 1 had a small mermithid. By killing flies from which they exited, the worms prevented females from taking a second blood meal.

Although flies were killed by exit of the mermithid, this parasite is ineffective against the major pest species, Simulium arcticum Malloch, because it does not prevent parasitized females from seeking and taking a blood meal and thereby harassing cattle. However, in years when nearly 50% of the emerged adults are parasitized (like 1974), this mermithid may be a principal factor regulating the population density of the S. arcticum population in subsequent years.

The larvae of jack pine budworm, Choristoneura pinus pinus Free., were reared individually on diet in the laboratory. Observation of ecdysis and measurement of the corresponding head capsules identified seven distinct instars. Parasitism by the common larval parasitoid Apanteles fumiferanae Vier. resulted in smaller head capsule size and retarded development during the fourth, fifth, and sixth instars of the jack pine bud worm.

Spring-felled logs of Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, and western hemlock, Tsuga heterophylla (Raf.) Sarg., were attacked by ambrosia beetles, Trypodendron lineatum (Oliv.), in the year after felling. By monitoring individual galleries it was determined that brood production was similar to that found in fall- and winter-felled logs. The sex ratio of the brood did not differ significantly from 1:1. Only beetles that had failed to establish successful galleries emerged during the "second" flight period. Significant linear relationships were found between frass weight and each of the following variables: number of egg niches, emerged adult progeny, and gallery length. Mortality in galleries in Douglas-fir and western hemlock logs, respectively, was found to be 9.4 and 12.4% between the egg and larval–pupal stage and 19.5 and 32.1% between the larval–pupal and adult stages.

Overwintered adults of Dendroctorms simplex LeConte emerged in May and June and produced one generation and two broods in 1983 and 1984. Egg galleries were vertical, slightly sinuous, and significantly longer in first brood trees than in second brood trees . Females laid zero to four eggs per niche . The average number of eggs per gallery was significantly higher in first brood trees (48) than in second brood trees (31). Mean number of eggs per centimetre of gallery was 1.2 for both broods. Mean brood density was significantly higher in first brood trees (50 individuals per 100 cm2) than in second brood trees (23 per 100 cm2).

Dendroctonus simplex has four larval instars. Development from egg to adult in the field averaged 60 and 70 days for first and second broods, respectively. Total development at 12, 18, and 24°C in the laboratory averaged 80, 42, and 39 days, respectively. Adult males were significantly smaller than females.

The reproductive cycles of the red turnip beetle, Entomoscelis americana Brown, were studied in the field in Manitoba from 1974 to 1978. Vitellogenesis is initiated within the first 3 days after emergence from aestivation in early August. Oviposition begins soon after the first eggs are developed, usually within the first 8 days after emergence. The rate of egg laying reaches a peak within 2 weeks after the initiation of oviposition and then declines gradually during the remainder of the oviposition period. Almost all eggs were laid between mid-August and mid-October. The average numbers of eggs laid per mated female in three oviposition studies were as follows: 1 female per cage (1974), 254±74 (±SE) (range, 11–696); 1 female per cage (1976), 273±47 (range, 0–622); and 25 females per cage (1974), 426±3 (range, 392–462). The most eggs were laid at the lowest temperature regime tested (6–20°C; mean, 12°C). Copulation is initiated in males and females during the 1st day after emergence from aestivation and both mate many times. Stimuli associated with copulation and (or) insemination enhance egg output, but are not required for the initiation of vitellogenesis and oviposition. Males transfer sufficient spermatozoa to the females during the first one or more copulations that occur during the first 8 days after emergence to fertilize almost all eggs produced. A system for classifying the stages of oocyte development is described.

The Donacia subtilis species-group, comprising D. subtilis Kunze, D. fulgens LeConte, D. confluenta Say, and D. tuberculifrons Schaeffer, is newly defined. A key to species, and genitalic figures of males for the species are given. Types are designated for all names where necessary. Donacia cuprea Kirby, 1837 (lectotype female, BMNH, designated herein), the oldest name available for D. quadricollis, auctorum, is revalidated. Donacia quadricollis Say, 1827 (neotype male, MCZ, designated herein) is newly placed as junior subjective synonym of D. subtilis Kunze, 1818. Donacia confluenta Say, 1827 (neotype male, MCZ, designated herein) is removed from synonymy of D. subtilis Kunze on the basis of differences in male genitalic structure. Donacia magistrigata Mead, 1938, is transferred from junior subjective synonymy of D. fulgens LeConte, 1851 (lectotype male, MCZ, designated herein) to junior subjective synonymy of D. subtilis Kunze, on the basis of similarity of male genitalic structure. The collection of Ahrens is lost, therefore a neotype for D. aenea Ahrens, 1810, not Hoppe, 1795, is designated (CNC, male). Donacia aerea Lacordaire, 1845 (lectotype, male, BMNH, designated herein) remains as junior subjective synonym of D. subtilis Kunze.

Adult flea beetles, Phyllotreta cruciferae (Goeze), P. striolata (F.), and Psylliodes punctulata Melsh., overwintering in the litter of a riverbank forest at Winnipeg, Manitoba, varied in density from about 1.4 million to 2.5 million beetles per hectare from 1979 to 1983. Phyllotreta cruciferae was the most abundant species (78–92%) and P. striolata next (6–22%) in litter samples collected in the late autumn, just before the ground froze. The distribution of beetles was highly aggregated (variance/mean ratio > 1.0) for P. cruciferae and P. striolata in years of high density but this ratio was 1.0 (random distribution) when densities were below 1.0 per square metre. Density was positively related to the amount of litter and increased from the edge to the center on the south side of the grove. On the north side, densities were highest at the edge of the grove. Survival in the litter during the autumn was generally lower and more variable than during the winter or spring periods. Survival in the litter during the 4 years ranged from 0.22 to 0.46 for P. cruciferae and from 0.31 to 0.83 for P. striolata. Temperature, through its effect on the time of emergence of adults in late summer and autumn, may affect their ability to survive the onset of cold weather.

A distribution study of stored-product and other insects in unswept, empty farm granaries was conducted in Manitoba in 1981, in Saskatchewan in 1982, and in Alberta in 1984.

Thirteen species of stored-product insects were found in Manitoba and Saskatchewan and 12 in Alberta, indicating uniform geographical distribution among the number of pest species throughout the prairies. The most common was Tribolium audax Halstead, followed by Cryptolestes ferrugineus (Stephens) and Tenebrio molitor L. Nine fungus-feeding species were found in Manitoba, 12 in Saskatchewan, and 12 in Alberta. The most common fungus feeders were Lathridius minutus (L.), Corticarina cavicollis Mann., Cryptophagus varus W.&C., and Corticaria serrata (Paykull). Five non-stored product species of insects that were scavengers, predators, or were sheltering in the granaries were found in Manitoba, 31 in Saskatchewan, and 10 in Alberta.

The distribution of six stored-product species, two fungus-feeding species, and one scavenger did not show a uniform abundance in the three prairie provinces, either in their distribution on farms or in granaries.

The species of the subgenus Castaneomyzocallis subg. nov. (genus Myzocallis) are found in North America on Castanea. Four species are classified in this subgenus: M. (C.) castaneae (Fitch) (type of subgenus); M. (C.) tissoti nom. nov.; M. (C.) nanae (Tissot); and M. (C.) castaneoides (Baker). The neotype of M. (C.) castaneae is established. The alate viviparae, the embryos, and the alatoid nymphs of M. (C.) castaneae, M. (C.) castaneoides, M. (C.) tissoti, and M. (C.) nanae are described. A key for the identification of the new subgenus is given. Attention is drawn to variations that may be caused by seasonal factors.

A new genus and species of psenine wasp are described: Lithium cicatrix. Relationships with other genera are discussed, new tribal limits are proposed, and a key to genera of psenine wasps is presented.

Noctua pronuba L. is now abundant in central Nova Scotia and has become established throughout the province, on Sable Island, Prince Edward Island, and in Newfoundland. Sporadic records indicate that this species has become established in New Brunswick and is spreading into Maine. Light-trap records illustrate the rapid population increase in Nova Scotia and the spread throughout the Atlantic Provinces.

By injecting fenitrothion into fluid in leaves of pitcher plants, Sarracenia purpurea L., it was determined that the mosquito, Wyeomyia smithii (Coquillett), and the midge, Metriocnemus knabi (Coquillett), are under some risk from fenitrothion forest sprays at the rate of 210 g AI/ha. Wyeomyia smithii is slightly more susceptible than is M. knabi. Other leaf inhabitants, mites and rotifers, were not affected by initial concentrations of fenitrothion in the fluid (up to 9.6 μg/L) that did affect the mosquito and the midge.

Developmental times were determined at constant temperatures for egg–larval (prepupal) and egg–larval–adult (preadult) house flies in poultry manure. Developmental time decreased as temperature increased but declined at temperatures above 35°C. The average time from oviposition to pupation ranged from 26.8 days at 16°C to 5.2 days at 35°C, and the average time to adult emergence ranged from 43.1 to 8.8 days. Pupae were formed at 41°C, but no adults emerged above 38°C. The relationship between developmental rate and temperature was determined and used in a rate summation model to simulate prepupal and preadult developmental times in poultry manure, with manure bed temperature as input. The model was tested on the basis of developmental times determined in a poultry house during the fly-breeding season. The observed mean time to pupation under field temperatures ranged from 6.7 to 15.6 days, and adult emergence required from 12.5 to 27.1 days. Simulations were closest to the observed times when actual manure bed temperatures were used as input; however, soil temperatures obtained from a nearby weather station also provided satisfactory simulation results after an empirical correction was used.

Theridion strepitus sp. nov. is described from lava tube caves from Isla Santa Cruz, Galápagos, Ecuador. It is the only species known in this worldwide genus that is eyeless and it is the only Galápagos species that has stridulatory picks on the male abdomen. The stridulatory apparatus demonstrates that the species is not a descendant from the other Theridion species known in the Galápagos, but is probably a relict of a lineage now extinct there in epigean habitats.

A discussion is presented about specimens that are morphologically intermediate between Nephrotoma ferruginea (Fab.) and N. suturalis suturalis (Loew). The specimens came from far outside the present ranges of these two species, namely Kerrville, Texas. It is concluded that the specimens might represent a population of hybrids. It is further estimated that the withdrawal of the parental species from central Texas could possibly have occurred a thousand years ago or earlier.